Organ-stop knob



(No Model.)

CLARK.

ORGAN STOP KNOB. No. 392,990. Patented Nov. 20, 1888.

I. in

PATENT Farce.

MELVILLE CLARK, OF CHICAGO, ILLINOIS.

ORGAN=STOP KNGB.

SPECIFICATION forming part of Letters Patent No. 392,990, dated November 20, 1888.

Application filed April 537, 1883. Serial X0. 272,029. (No model.)

.To aZZ whom it may concern.-

Be it known that I, MELVILLE CLARK, a citizen of the United States, residing at Ohieago, in the county of Cook and State of 1lli nois, have invented certain new and useful Improvements in Organ-Stop Knobs, which are fully set forth in the following specification.

Figure 1 is an axial section of a hollow metal organ-stop knob and its shank, showing the parts in the position they will occupy relatively before the knob is tightened on the shank. Fig. 2is asimilar axial section showing the knob moderately tightened on the shank. Fig.3 is asimilarsection showing theknob completely tightened on the shank. Fig. at is an axial section of a modified construction of a stop-knob and its shank, showing parts con nected but not thoroughly tightened together. Fig. his a similar section showing parts tightened together. Fig. 6 is an axial section of a hollow stopknob and its shank connected according to the modified construction shown in Figs. at and 5 and firmly tightened together. Fig. 7 is an axial section of a knob and its shank, in which the form of the shank is slightly modified from those shown in the preceding figures. Fig. 8 is a front elevation of a stop-knob in a position corresponding to that shown in Figs. 1 and 4.. Fig. 9 is a similar elevation correspondingin position to Figs. 3 and 5.

A is the knob. 13 is the shank. G is a washer interposed between them; D,the screwstem by means of which it is attached to the shank.

This invention consists in forming the knob and its shank so that the force exerted by the screw which unites them in drawing them together shall produce pressure only at the periphery of the lesser part and this result is accomplished by concaving one of said parts toward the other over the entire extent of the one of less diameter.

I will describe first this invention as applied to hollow metal knobs. It consists, primarily, in forming the base A of the knob concave toward the end of the shank. This construction is designed to adapt the knob to be tightened upon the shank by means of the screw stem which connects the knob and shank and to be turned any amount less than three hundred and sixty degrees after it has become sufficiently tightened without breaking loose the screw-stem or wearing out the thread which the screw-stem will cut in the end of the shank, which is of wood, and into which said screwstem is necessarily inserted parallel with the grain of the wood, so that the thread which the screw forms might easily be worn out and the screw entirely loosened in the wood, if it were forcibly turned therein, without opportunity to advance longitudinally.

The necessity for sometimes making a half turn, and even in some cases almost a full turn, of the knob after it is sufficiently rigid with the shank arises in organ-stop knobs in which the stop-name is permanently formed or marked upon the face of the knob, since it is necessary that that name should be set right side up and extending in the proper direction, which is usually horizontal, and it is not possible to so accurately construct the parts that the knob will first cometight with the name in the proper position. The concavity of the base of the knob is adapted to accomplish this purpose on two accounts: First, it is customary and desirable to insert a washer of felt or other soft and compressible substance between the end of the shank and base of the knob to cover the portion of the knob which projects all around the shank, and stops the knob when it is pushed back through the stop-board, so that the contact of the knob and stop-board shall not cause undue noise. By concaving the end of the knob over so much of its surface, at least, as abuts against the end of the shank, the felt or leather washer interposed between them is compressed only in the circumference of a circle where the shank would come in contact with the concave end of the knob if the washer were not interposed, and while it would not be possible to compress the entire substance of the washer covering the end of the shank so much as to permit nearly a full turn of the knob after it was already screwed tight enough to be sufficiently rigid with the shank, it is easily possible to give it one full turn when in so doing it is necessary only to pinch the washer in the circumference of the circle instead of over its entire area, for the material of the washer will not necessarily be compressed by the amount that the knob is forced closer to the shank in that one turn; but the edge of the shank will crowd the substance of the washer aside, thickening it in the concavity of the base of the knob, and the knob will be scarcely more tight on the stem upon being revolved one extra turn than before such extra turn is made. This result is further assisted by concaving also the end of the shank, as shown in the several figures, thereby reducing the edge of the shank, which brings the washer to a sharper angle, and increasing its tendency to force aside the substance of the washer when the knob is tightened, as described.

The foregoing reason why the coneaving of the end of the knob accomplishes the result aimed at is equally applicable to a solid knob of any material; but in the case of a hollow metal knob the form described is effective in accomplishing the result sought for a second reason-via, that when the base of thehollow metal knob is thus formed concave toward the head of the shank, and the screw-stem is secured to the center of that concave base, such base has sufficient elasticity to yield toward the head of the shank, while the knob is given the additional turn which may be neccs sary to bring the name into proper position, and while thus elastic it is nevertheless sufficiently rigid to afford enough resistance to hold the knob rigidlyin position on the shank, whether it is thus drawn down or not. \Vhen it is necessary to turn the knob after it is tight to bring the name into the correct position in the case of such a hollow metal knob, this base will yield, so that it will take substantially the form shown in Fig. 7.

Either in the use of the hollow metal knob or solid knob having the concave base, the washer C, of felt or leather, may be omitted without depriving the construction of the capacity for adjustment of the knob in the manner and for the purpose described, because, as above shown in the case of the hollow metal knob, the elasticity of the concave base itself gives the necessary range of adjustment, and even if the base of such hollow metal knob were too firm to yield, as described, the concavity in the base impinging against the pe riphery only of the end of the wooden shank will, if the knob is made sufficientlyconcave, crowd the corner of the wood inward and bevel it enough to allow the necessary adjustment, unless in the case of extremely hard wood. The same effect, obviously, will be more surely produced and the adjustment desired thereby obtained in the case of solid knobs, and such knobs, both of porcelain and other pottery-ware and of cast metal,are often used.

For a further understanding of the drawings, A represents the face or forward end of the knob, upon which a represents the lettering for the nameof the stop.

I claim-- 1. In combination, substantially as set forth, an organ-stop knob and its shank, one of said parts being concave toward the proximate end of the other, the knob having a screw-stem protruding from its base and screwed into the end of the shank.

2. In combination with the knob and its shank, one of said parts being concavetoward the proximate end of the other, a washer of compressible material interposed between them, the knob having a screw-stem protruding into the end of the shank and constituting the means of securing the knob and the shank together, substantially as set forth.

3. In combination with the shank, ahollow metal stopknob having a screwstem protruding from its base and constituting a means of securing it to its shank,said base being formed concave toward the end of the shank and convex toward the face of the knob, substantially as and for the purpose set forth.

In testimony whereof I have hereunto set my hand, in the presence of two witnesses, at Chicago, this 24th day of April, 1888.

M ELVILLE CLARK.

Witnesses:

CHAS. S. BURTON, E. F. BURTON. 

